Mildewcide for paint

ABSTRACT

PAINTS CAN BE MADE RESISTANT TO FUNGAL ATTACK BY THE INCORPORATION THEREIN OF 2-BENZIMIDAZOLECARRBAMIC ACID, METHYL ESTER IN ADMIXTURE WITH A SECOND FUNGICIDE OR MIXTURE OF FUNGICIDES SELECTED FROM THEYLENEBIS (DITHIOCARBAMIC ACID), ZINC SALT; DIMETHYLDITHIOCARBAMIC ACID, ZINC SALT; 3,4&#39;&#39;,5-TRIBROMOSALICYLANILIDE; TRIBUTYLTIN FLUORIDE OR OXIDE; 2-MERCAPTOPYRIDINE-N-OXIDE, ZINC SALT; OR VARIOUS PHENYL MERCURIC ESTERS.

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3,817,761 MILDEWCIDE FOR PAINT Loren D. Brake, Wilmington,Del.,.assignor to E. I. du Pont de Nemours and Company, Wilmington, Del.No Drawing. Filed Apr. 18, 1973, Ser. No. 352,291 Int. Cl. C09d /14 US.Cl. 106-15 AF 11 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THEINVENTION Mercury compounds, such as phenyl mercuric acetate, phenylmercuric propionate, phenyl mercuric succinate and phenyl mercuricoleate have been used extensively as fungicides in film-formingcompositions such as paint. However, recently the use of these mercurycompounds is being curtailed in view of possible toxicity problems,particularly when they are employed at high use levels.

Other types of compounds have been proposed for use as fungicides inpaint, including benzimidazole type fungicides, see US. Pats. 2,933,502,2,933,504, 3,541,- 213, 3,631,176 and German Patent Application No.2,040,069 published Feb. 17, 1972.

However, the need still exists for a safe fungicide for use in paintcompositions. Difiiculties have been encountered in meeting this needbecause of the special requirements of this use. Thus the fungicide mustnot only provide effective fungicidal protection for an extended periodof time, both in the formulation and in the applied film, but it mustalso be compatible with the other com ponents of the formulation, and itmust not adversely affect the film appearance or properties.

SUMMARY OF THE INVENTION aai in admixture with a second fungicide ormixture of fungicides selected from (i) ethylenebis(dithiocarbamicacid), zinc salt 3,817,761 Patented June 18, 1974 (ii)dimethyldithiocarbamic acid, zinc salt (iii) 3,4,5-tribromosalicylanilide 0H Br (iv) tributyltin fluoride, (C H SnF (v) tributyltinoxide, [(C H Sn] O (vi) Z-mercaptopyridine-N-oxide, zinc salt III (vii)phenyl mercuric acetate (viii) phenyl mercuric propionate (ix) phenylmercuric succinate (x) phenyl mercuric oleate The above mixture is addedto paint in the following proportions from 5-20,000 parts per million byweight of the benzimidazole and from 550,000 parts per million by weightof the second fungicide or mixture of fungicides.

DESCRIPTION OF THE INVENTION The components of the mildewcide mixture ofthe invention are known fungicides. Methods for the preparation ofseveral of the compounds can be found in the following references:

2-benzi-midazolecarbamic acid, methyl ester-US. Pat. 3,010,968 to Louxand US. Pat. 3,657,443 to Klopping;

ethylenebis(dithiocarbamic acid), zinc saltU.S. Pat.

dimethyldithiocarbamic acid, zinc salt--U.S. Pat. 2,229,-

3,4,S-tribromosalicylanilideU.S. Pat. 2,967,885;

tributyltin fluorideU.S. Pat. 3,036,103;

tributyltin oxide-Chem. Eng. Progress, 58, No. 9, 71-52-mercaptopyridine-N oxide, zinc salt-US. Pat. 2,809,-

The mixtures of the invention offer a safe, elfective fungicide forfilm-forming compositions. Fungus mycelia are killed or prevented fromdeveloping by the presence of these mixtures, i.e., the mixture isfungicidal or fungistatic. The mixtures are active against many speciesof fungi, including the various species of the classes: Penicillium,Aspergillus, Ceratostamella, Aureobasidium, Botrytis, Cladosporium,Fusarium and Curvularia, which fungi grow on paint, fabric, paper, wood,fiberboard, and leather goods.

The mixtures of this invention also make possible the control of damageby fungi with an amazingly small amount of chemical and surprisinglylittle effort. These advantages are due in large measure to the factthat the mixtures when properly applied, can prevent the growth of fungiin film-forming compositions. This means that the treated surface can beprotected from fungi with the application of the mixture in thefilm-forming or coating composition. The mixtures also have the propertyof protecting the film-forming composition prior to application, i.e.,they act as fungicidal preservatives for the paint, etc. in thecontainer.

Luggage, shoes, leather, shower curtains, carpets, mats, clothing,grouting, wood, fiberboard, caulks, sealants, adhesives, joint cements,roofing materials, tenting, fabric and other useful household, public orindustrial items are also protected from rot, fungus stains andunsightly mold growth by the mildewcide mixtures of this invention.Either surface or deep protection can be obtained. Surface treatment isby dips, washes, sprays, aerosols or dust applications. Deep treatmentis accomplished by penetrating solutions or by incorporation into thematerial. Protection from unsightly stain and mold growth is achieved byincorporating 540,000 parts per million by weight of the benzimidazoleand 550,000 parts per million by weight of the other fungicide ormixture of fungicides. More preferred rates are in the range of 100-5000parts per million by weight of the benzimidazole and 50-15,000 parts permillion by weight of the other fungicides or mixtures of fungicides andthe most preferred rates are in the range of 3002,000 parts per millionby weight of the benzimidazole and 75-10,000 parts per million by weightof the other fungicide or mixture of fungicides.

The most efficient distribution and utility of the active fungicidalcomponents of the mixture will be realized if their particle size isless than 50 microns. Larger particle sizes can, of course, be used;however an effective distribution in the resulting film will requirehigher concentrations to achieve the desired protection. The desiredparticle size can be obtained using grinders, e.g., sand grinder, ballmills, micropulverizers, air mills, or other methods known in the art.-A combination of two or more of the pulverizing methods may beemployed.

The mixture can be incorporated into the film-forming composition in theamounts and by the techniques described in the following paragraphs.

The mixture is present in the compositions in an amount such that solidfilms prepared from the compositions have useful fungicidal propertiesfor the particular end-use application. One skilled in the art, afterrealizing the essence of the invention set forth in this disclosure,will be able to select the fungicide concentration that gives the bestcombination of film physical properties and fungicidal properties in thefinal product for the particular composition and application methodemployed in the practice of this invention. If not enough activefungicide is present, films of the composition will not have sufiicientfungicidal properties, either initially or after a short period of use.If too much fungicide is present, films of the composition tend to beunduly expensive.

Coated surfaces and their substrates can be protected from unsightlystain and mold growth by incorporating in the film-forming formulation,prior to application, 5 to 20,000 parts per million by weight of thebenzimidazole and 5 to 50,000 parts per million by weight of the otherfungicide or mixtures thereof. Such treatments with the active mixturealso protect the paint while still in the can from deformation by fungi.

It is preferred that the benzimidazole be in the range of IOU-5,000parts per million by weight, the most preferred range is 300-2000 partsper million by weight.

The other fungicides can be divided into two groups. Group A includesethylenebis(dithiocarbamic acid), zinc salt; dimethyldithiocarbamicacid, zinc salt; and 3,4,5- tribromosalicylanilide. Group B includestributyltin fluoride; tributyltin oxide; phenyl mercuric acetate; phenylmercuric propionate; phenyl mercuric succinate; phenyl mercuric oleate;and 2-mercaptopyridine-N-oxide, zinc salt.

It is preferred that the compounds of Group A be used in the range of1,000-15,000 parts per million by weight, the most preferred range is3,00010,000 parts per million by weight. It is preferred that thecompounds of Group B be used in the range of 0-3,000 parts per millionby weight, the most preferred range is 75-l,000 parts per million byweight. At these levels the mercuric compounds do not present serioustoxicity problems.

The preferred second fungicide selected from Group A isethylenebis(dithiocarbamic acid), zinc salt and dimethyldithiocarbamicacid, zinc salt; the most preferred is ethylenebis(dithiocarbamic acid),zinc salt; and from Group B is tributyltin fluoride and the mercurialcompounds; the most preferred is the mercurial compounds.

Paint resistance to fungal attack can be improved by the addition of1-10 parts per hundred by weight of finely divided zinc oxide with5-20,000 parts per million by weight of the benzimidazole to thefilm-forming compositions. Preferred rates are in the range of 3-7.5parts per hundred by weight of the zinc oxide and 300-2,000 parts permillion by weight of the benzimidazole. Improved resistance to fungalattack is also obtained by the incorporation of a benzimidazole inadmixture with a second fungicide or mixture of fungicides of thisinvention with zinc oxide in the film-forming compositions. This isreadily accomplished in many instances as many paint formulationscontain zinc "oxide for other purposes, i.e., as a paint pigment.

Preferred embodiments of the novel compositions are in the form ofliquid coating compositions wherein the mixture of film-former and theactive mixture is dispersed in a liquid adapted for use in preparing afilmformer solution or suspension.

For example, very beneficial results are obtainable when the compositionis in the form of a latex paint or latex adhesive wherein (1) the liquidphase is predominantly water, (2) the resin or other film-forming isinsoluble in the liquid phase, and (3) the film-forming components andthe fungicide mixture are present as very small particles suspended oremulsified in the liquid.

Good results are also obtainable when the liquid phase in which thefilm-forming components and the fungicide mixture are dispersed ispredominantly a volatile organic liquid, and film-former is present as asolution in said liquid.

The term film-forming compositions as used in this application, is meantto cover paints such as alkyd, acrylic, vinyl acrylic, alkyd modifiedacrylic or alkyd modified vinyl acrylic paints, enamels, lacquers,varnishes, or any other film-former or binder which is known in the artto be useful in the manufacture of solid (nonliquid) films or coatings.The term film-former refers to the polymer, e.g., synthetic resins,natural resins or elastomers, wax, drying oil component, or mixturesthere of present either in the formulation prior to application or inthe final film. Film-formers are sometimes referred to in the art asbinders, especially in compositions containing pigments or fillers.

Typical formulations for film-forming compositions are described in thefollowing U.S. patents, U.S. 3,261,796, U.S. 2,863,752, U.S. 2,868,754,U.S. 2,787,603, U.S. 3,113,038 and U.S. 3,032,521 and in Formulation ofOrganic Coatings by N. I. Gaynes, D. Van Nostrand Co., Inc. (1967).

One type of film-former which can be used, especially when thecomposition is a latex, is one composed of about 50-100% by weight of anamine ester polymer which may be defined as a vinyl addition polymerhaving attached to the carbon-carbon chain monovalent radicals of theformulas wherein R is selected from the group consisting of hydrogen,benzyl and C -C alkyl radicals, and R and R are selected individuallyfrom the group consisting of hydrogen, benzyl, aryl and C -C alkylradicals, and R is selected from the group consisting of hydrogen and C-C alkyl radicals. In this preferred kind of composition, about 1-50% byweight of the film-former can be composed of another film-former whichone skilled in the art can select as having suitable compatibility withsaid aminoester polymer. Said amino-ester polymer can be prepared byvarious methods well-known in the art; for example, according to theprocedure described in US. Pat. 3,261,796.

Another useful type of film-former to use in both the latex and solutioncompositions is one composed of about 50100% by weight of an acrylicpolymer selected from the group consisting of poly(alkylacrylates),poly(alkylmethacrylates), and copolymers of an alkylacrylate and analkylmethacrylate.

Other useful film-formers are alkyd resins, oil-modified alkyd resins,formaldehyde condensate resins, epoxy resins, cellulose ester resins,shellac, vinyl chloride resins, fluorine-containing resins,styrene/alkyl acrylate/methacrylic acid copolymers, polyurethanes,acrylonitrile/ alkyl acrylate copolymers, acryloxy alkyl-oxazolideneresins, and mixtures of two or more such film-formers.

For aerosol spray application, the composition can be packaged in knownaerosol containers along with any suitable propellant, for example,dichlorodifiuoromethane.

The composition can contain one or more of the additives known to beuseful in film-forming compositions, for example curing agents, driers,anti-freeze agents, pigments, Wetting agents, anti-foamers, coalescentagents, odor controllers, a bactericide, plasticizers, stabilizers,viscosity controllers, surfactants and anti-settling agents. The use ofa bactericide is often particularly desirable to complement thefungicidal compounds in protecting the filmforming composition both inthe can and once applied.

The active fungicide mixture can be incorporated into the film-formingcomposition in a variety of ways as will be apparent to one skilled inthe art. For example, the mixture can be added as a fine powder to theotherwise completed formulation, and the composition stirred until auniform mixture is obtained. Alternatively, the powdered mixture may beblended with the film-former or with the pigment if one is used, priorto formulation.

It is particularly desirable to incorporate the fungicide mixture intothe film-forming composition prior to any grinding or blending stepwhich would normally be in preparing the formulation. In this way, thefungicide mixture is uniformly dispersed and no extra grinding orblending step is required.

A preferred procedure for paint formulations, where the pigment must beground or disaggregated and dispersed in the vehicle, is to add thefungicide mixture prior to this grinding step.

In the interest of avoiding any undue harm to the active ingredients,the compositions of the invention preferably have a pH of about 1-10 anda processing temperature in forming the solid film of less than 200 C.if the temperature is to be applied over a period of several hours, orif shorter times are involved, temperatures up to 300 C. can betolerated.

The composition can be formed into solid films or coatings by anysuitable known coating or film-forming method; for example, spraying,rolling brushing, knifespreading, dipping, calendering, extruding,electrocoating, flow coating, or by a powder coating process wherein alayer of powdered coating composition is converted to a solid film(e.g., by a heating or hot-pressing method followed by cooling).However, the processing limitation previously set forth should beconsidered in utilizing these methods.

Paints, lacquers, adhesives and other types of film-forming compositionsare obtainable according to the present invention which have beneficialutility for the preparation of solid films and coatings. For example,these compositions enable one to prepare coatings having a verydesirable combination of properties including (1) effective initialfungicidal characteristics, (2) low toxicity to humans and warm-bloodedanimals, (3) satisfactory durability, adhesion, appearance and thelike;.(4) reasonable cost, (5) surprising ability to prevent or inhibitgrowth of fungi even after repeated exposure to rain and sunlight.

The compositions are very useful for coating articles and surfaces whichare likely to be used under conditions which favor the growth of fungi,for example, in warm, humid areas. The utility of the compositions isespecially beneficial in applications were low toxicity to humans andwarm-blooded animals is important, for example, in coating the interiorof buildings used for the manufacture of food and medicines.

A variety of substrates may be protected by the incorporation of thecompounds of this invention into film-forming compositions which arethen applied to the substrate and result in an adherent, solidifiedlayer. Wood, fabric, metal, leather, polymer coated, or polymeric sheetmaterials, fiber board, paper and other industrial materials areprotected from unsightly stain and destructive decay cause by fungi.

The following examples are offered to illustrate the film-formingcompositions of the invention.

EXAMPLE 1 A latex house paintformulation contains the followingingredients:

Parts by weight Hydroxyethyl cellulose (2.5% solution) Water 68.5Nonionic dispersing agent: Tamol 731 (25% sold by Rohm & Haas 15 Wettingagent: Triton CF-IO, sold by Rohm &

Haas 2.5 Antifoarner: Nopco NDW, sold by Nopco 1 Ethylene glycol 25Non-chalking rutile titanium dioxide 250 Talc 203.7

The above materials are ground in a high-speed mill and let down, at aslower speed, as follows:

I Parts by weight Acrylic resin: Rhoplex AC-388 (50%), sold by Rohm &Haas 459.8 Antifoarner: Nopco NDW 1 Premix:

Ammonium hydroxide (28%) 2 Tributyl phosphate 11.5 Propy ene g yc 35Water and/or hydroxyethyl cellulose (2.5 17.5

To 1000 parts of the paint formulation described above is added 2 partsof finely divided 35 microns) 2-benzimidazolecarbamic acid, methyl esterand 6 parts of ethylenebis(dithiocarbamic acid), zinc salt. Theresulting mixture is then thoroughly mixed.

Clapboard siding can be painted with two coats of the completed latexpaint, using an ordinary paint brush. The paint film, after beingallowed to air dryand age under ordinary atmospheric conditions willhave excellent resistance to fungal attack, cracking and blistering andgood retention of appearance in general.

The clapboard siding substrate can be either new or a siding that hasbeen previously painted.

Equal weights of the following compounds can be substituted for theethylenebis(dithiocarbamic acid), zinc salt:

dimethyldithiocarbamic acid, zinc salt 3,4',5-tribromo salicylanilide.

7 EXAMPLE 2 An oil base house paint formulation containing the followingingredients is used in the following test.

Parts by weight TI-PURE R-966 (titanium dioxide) 300 Talc, stir-in grade315 Long oil alkyd, Dyal XAC-Cl29 sold by 'Sherwin- Williams Co. 400 24%lead naphthenate 6.9 6% manganese naphthenate 1.4 Heavy mineral spirits169 To 1000 parts of the paint formulation described above is added 2parts of 2-benzimidazolecarbamic acid, methyl ester and 7.5 partsethylenebis(dithiocarbamic acid), zinc salt. The resulting mixture isthoroughly mixed. A clapboard siding can be painted with two coats ofthis fungicidal oil base formulation, using an ordinary paint brush.After the paint film is allowed to dry, the clapboard will be resistantto fungal attack.

An equal weight of the following compound can be substituted for theethylenebis (dithiocarbamic acid), zinc salt: 3,4,5-tribromosalicylanilide.

EXAMPLE 3 A latex house paint formulation contains the followingingredients:

Parts by weight Hydroxyethyl cellulose (2.5% solution) 85 Water 68.5

Nonionic dispersing agent: Tamol 731 (25% sold by Rohm & Haas l5 Wettingagent: Triton CF-lt), sold by Rohm &

Haas 2.5 Antifoamer: Nopco NDW, sold by Nopco 1 Ethylene glycol 25Non-chalking rutile titanium dioxide 250 Talc 203.7

The above materials are ground in a high-speed mill and let down, at aslower speed, as follows:

Parts by weight Acrylic resin: Rhoplex AC-388 (50%) 390.8 Long oilalkyd: Cargill 7700, sold by Cargill, Inc. 30.8 Antifoamer: Nopco NDW 1Premix:

Ammonium hydroxide (28%) 2 Tributyl phosphate 9.8 Propylene glycol 35Water and/ or hydroxyethyl cellulose (2.5%) 53.5

To 1000 parts of the paint formulation described above is added 1 partof finely divided 35 microns) 2-benz= imidazolecarbamic acid, methylester and 1 part 2-mercaptopyridine-N-oxide, zinc salt. The resultingmixture is then thoroughly mixed.

A clapboard siding can be painted with two coats of the completed alkydmodified latex paint, using an ordi nary paint brush. The paint filmafter being allowed to air dry and age under ordinary atmosphericconditions will have excellent resistance to fungal attack.

Equal weights of the following compounds acn be sub stituted for the2-mercaptopyridine-N-oxide, zinc salt:

tributyltin fluoride; tributyltin oxide.

8 EXAMPLE 4 A latex house paint formulation contains the followingingredients:

Parts by weight Water 65 Ethylene glycol Anionic dispersing agent: Tamol850, sold by Rohm & Haas 10 Nonionic wetting agent: Igepal CTA-639, soldby GAF Corp 3 Antifoamer: Colloid 677, sold by Colloids, Inc. 1Thickener: Natrosol 250 HR (1.5% solution), sold by Hercules, Inc.Non-chalking rutile titanium dioxide 275 Extender: Optiwite, sold byBurgess, Inc. 35 Celite 281, sold by Johns-Manville 25 The abovematerials are ground in a high-speed mill and let down, at a slowerspeed, as follows:

Parts by weight Water 46 Vinyl acrylic resin: Resyn 2345, sold byNational Starch and Chemical Corp. 364 Nonionic wetting agent: IgepalCTA-639 6.5 Antifoamer: Colloid 677 1.5 coalescent: Carbinol Acetate,sold by Union Carbide l2 Thickener: Natrosol 250 HR (1.5% solution) 66To 1000 parts of the paint formulation described above is added 0.5 partof finely divided 25 microns) 2-benzimidazolecarbamic acid, methyl esterand 5 parts dimethyldithiocarbamic acid, zinc salt. The resultingmixture is then thoroughly mixed.

A clapboard siding can be painted with two coats of the completed latexpaint, using an ordinary paint brush. The paint film after being allowedto air dry and age under ordinary atmospheric conditions will haveexcellent resistance to fungal attack.

Equal weights of the following compounds can be substituted for thedimethyldithiocarbamic acid, zinc salt:

ethylenebis(dithiocarbamic acid), zinc salt;3,4,S-tribromosalicylanilide.

EXAMPLE 5 To 1000 parts of the paint formulation described in Example 4is added 0.3 part of finely divided 35 microns Z-benzimidazolecarbamicacid, methyl ester, 2.5 parts 3,4,5-tribromosalicylanilide and 0.5 part2-mercap-= topyridine-N-oxide, zinc salt.

A clapboard siding can be painted with two coats of the completed latexpaint, using an ordinary paint brush. The pain film after being allowingto air dry and age under ordinary atmospheric conditions will haveexcellent resis= tance to fungal attack.

EXAMPLE 6 Celite 281, sold by Johns-Manville 25 The above materials areground in a high-speed mill and let down, at a slower speed, as follows:

Parts by weight Water 46 Vinyl acrylic resin: Resyn 2345, sold byNational Starch and Chemical Corp. 275 Nonionic wetting agent: IgepalCTA-639 6.5 Dryer:

6% cobalt naphthanate, sold by Nuodex, Inc. 1.5 24% lead naphthanate 3Long oil alkyd: Cargill 7700, sold by Cargill, Inc. 37.0 Antifoamer:Colloid 677 1.5

Coalescent: Carbinol acetate, sold by Union Carbide Thickener: Natrosol250 HR (1.5% solution) 66 Water 26.5

To 1000 parts of the paint formulation described above is added 5 partsof finely divided 40 microns) 2-benzimidazolecarbamic acid, methyl esterand 0.2 parts of phenyl mercuric propionate, The resulting mixture isthen thoroughly mixed.

A clapboard siding can be painted with two coats of the completed alkydmodified latex paint, using an ordinary paint brush. The paint-filmafter being allowed to air dry and age under ordinary atmosphericconditions will have excellent resistance to fungal attack.

Equal weights of the following compounds can be substituted for thephenyl mercuric propionate:

phenyl mercuric acetate; phenyl mercuric succinate.

.EXAMPLE 7 A latex house paint formulation contains the followingingredients:

Parts by weight 65 The above materials are ground in a high-speed milland let down, at a slower speed, as follows:

Parts by weight Water 46 Vinyl acrylic resin: Resyn 2345, soldbyNational Starch and Chemical Corp. 414.9 Nonionic wetting agent: IgepalCTA-639 6.5 Antifoamer: Colloid 677 1.5 Coalescent: Carbinol acetate,sold by Union Carbide Thickener: Natrosol 250 HR (1.5% solution) To 1000parts of the paint fomulation described above is added 1 part of finelydivided 40 microns) 2-benzimidazolecarbamic acid, methyl ester. Theresultingmixture is then thoroughly mixed.

Clapboard siding can be painted with two coats of the completed latexpaint containing zinc oxide, using an ordinary paint brush. The paintfilm after being allowed to air dry and age under ordinary atmosphericconditions will have excellent resistance to fungal attack.

10 EXAMPLE .8

To 1000 parts of the paint formulation described in Example 7 is added0.5 parts of finely divided 25 microns) 2-benzimidazolecarbamic acid,methyl ester and 5- parts dimethyldithiocarbamic acid, zinc salt. Theresult ing mixture is then thoroughly mixed.

A clapboard siding can be painted with two coats of the completed latexpaint containing zinc oxide, using an ordinary paint brush,- The paintfilm after being allowed to air dry and age under ordinary atmosphericconditions will have excellent resistance to fungal attack.

Equal weights of the-following compounds can be substituted for thedimethyldithiocarbamic acid, zinc salt:

ethylenebis(dithiocarbamic acid), zinc salt;3,4,5-tribromosalicylanilide.

EXAMPLE 9 To parts of the paint formulation described in Example 7 isadded 1 part of finely divided 35 microns) Z-benzimidazolecarbamic acid,methyl ester and 1 part tributyltin fluoride. The resulting mixture isthen thoroughly mixed.

A clapboard siding can be painted with two coats of the completed latexpaint containing zinc oxide, using an ordinary paint brush. The paintfilm after being allowed to air dry and age under ordinary atmosphericconditions will have excellent resistance to fungal attack.

Equal weights of following compounds can be substituted for thetributyltin fluoride:

tributyltin oxide; Z-mercaptopyridine-N-oxide, zinc salt.

I claim:

1. A method of protecting paint film from fungal attack comprisingincorporating into the paint prior to application from 5 to 20,000,p.p.m. by weight of 2-benzimidazolecarbamic acid, methyl ester and 5 to50,000 p.p.m.

by weight of a second fungicide or mixtures thereof selected from:

(i) ethylenebis(dith iocarbamic acid), zinc salt, (ii)dimethyldithiocarbamic acid, zinc salt, (iii) 3,4'5-tribromosalicylanilide,

(iv) 2-mercaptopyridine-N-oxide, zinc salt,

(v) tributyltin fluoride,

(vi) tributyltin oxide,

(vii) phenyl mercuric acetate,

(viii) phenyl mercuric propionate,

(ix) phenyl mercuric succinate, and

(x) phenyl mercuric oleate.

2. A paint composition comprising a mixture of a film former, 5 to20,000 p.p.m. by weight of Z-benzimidazolecarbamic acid, methyl ester,and 5 to 50,000 p.p.m. by zveight of a second fungicide or mixturesthereof selected rom:

(i) ethylenebis(dithiocarbamic acid), zinc salt, (ii)dimethyldithiocarbamic acid, zinc salt,

'(iii) 3,4'5-tribromo*salicylanilide,

(iv) Z-mercaptdiiyridine-N-oxide, zinc salt, (v) tributyltin fluoride,

(vi) tributyltin oxide,

(vfii) phenyl mercuric acetate,

(viii) phenyl mercuric propionate,

(ix) phenyl mercuric succinate, and

(x) phenyl mercuric oleate.

3. The composition of claim 2 in the form of a liquid coatingcomposition wherein the film-former and compound are dispersed in theliquid.

4. The composition of claim 2 wherein the liquid is water and thefilm-former is suspended in the water.

5. The composition of claim 2 wherein the liquid is a volatile organicliquid and the film-former is in solution in said liquid.

6. A coated article comprising a substrate having in adherence therewitha solidified layer of the composition of claim 2.

7. A paint composition comprising a mixture of a filmformer, 5 to 20,000p.p.m. of 2-benzimidazolecarbamic acid, methyl ester, and 1 to 10 partsper hundred of zinc oxide.

8. A coated article comprising a substrate having in adherence therewitha solidified layer of the composition of claim 7.,

9. A paint composition comprising a mixture of a filmformer, 300 to2,000 p.p.m. of 2-benzimidazolecarbamic acid, methyl ester and 3,000 to10,000 p.p.m. of ethylenebis-(dithiocarbamic acid), zinc salt. r

10. A paint composition comprising a mixture of a filmformer, 300 to2,000 p.p.m. of 2-benzimidazolecarbamic acid, methyl ester and 100 to1,000 p.p.m. of phenyl mercuric acetate, phenyl mercuric propionate,phenyl mercuric succinate or phenyl mercuric oleate.

11. The composition of claim 2 containing in addition 1 to 10 parts perhundred of zinc oxide.

References Cited UNITED STATES PATENTS 3,010,968 11/1961 Ioux 10615 AF5/1972 Dittmar 106-15AF HARRY WONG, 111., Primary Examiner US. 01. X.R.

15 117-427, 138.8, 140, 142, 147; 260-22 CB, 29.6 R,

